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Discussion in 'Systems & Severe' started by crikey, Jul 6, 2019.
The omega block over Southern Pacific is extraordinarily obvious over the next week.
What level is this at?
Looks like 70hPa, as nullschool only goes between 250/70/10hpa for the UA.
Thanks @POW_hungry for the blocking forecast.
Another concept that l will have to get my head around.
another possible consequence of the disruption to the surface layer ....after ....the significant disruption to the polar and sub polar stratosphere.
What is omega blocking..?
I can see the anomaly at sub polar latitude 120w. It looks like a massive mid latitude high falls into the sub polar belt and l suspect 'interrupts ?' the sub polar LOW belt.and the westerly wind belt
I saw one of those on the synoptic a few times closer to Australia a short while a go but my memory eludes me.
None the less you have posted the findings, with thanks and they can be analysed or discussed.
From me notes re sub polar jet currently
yes. I noted that as well. Thanks for posting .
The central dipole in the core is starting to close. I want to find out how long it takes
My apologies for the lack of Southern Hemi reference but you'll get the drift from this image example. Image correlates to multi-layer streams from jets to MSLP.
It's hall mark of weak PV events, such what our polar region is undergoing.
so can we look at the 10hpa and 250hpa as well?
Could you provide links
as an aside.
Did you know you can click on the outer wind band or maybe anywhere and get the speed of the wind stream at any GPS location
I accidentally did that tonight and the outer wind stream at around 70hpa was 148k/hr l think.
Interesting point.....the inner core has little wind .
Well thanks for the graphic . I have seen those on TV .and in my blog on NH Strat',warming events
It looks like that jetstream is there subpolar jet. A shame that diagram doesn't include the sub tropical jet as well
Will have to keep an eye on our 200hpa jets in the SH
For months l have noted our SH jet as zonal (straight)and strong.during the build up to event
We have spoken about a stratosphere warming pool bij the cold anomaly adjacent is equally impressive!!
Also keeping an open mind that the NH dynamics of sudden warmings may not be the same as the SH
and apologies fo KINO l have still not read that 2002 event documentation to make comparisons
If there was a quick and easy one stop shop for you I'd post it. I think there's too much confused hype accompanying the frenetic pursuit of this subject both here and on the Australian Weather Forum - can't see that it's adding much to understanding though - slow down...take a bit of time give it the time it deserves...it's not that easy....I always think of weather as being much more complex than computer science
Click the link (in my previous post), it's all in there as you requested.
OMG. That is sensational
trophy for you..!!
For context. I was ln a plane flight from Gold coast to Melbourne last year and the captain said we were going through 200km winds at top cruising height theough the jetstream.
Interesting that those outer winds of the polar vortex have similar velocity at 70hpa
Hmm ski forum tells me l have 2 trophys
addicted and can't stop..
Point to note. Those snaps are for forecast ,,13th July 2019
I believe we missed the opportunity on the 7th July.
But we have stacks of red hot data.
Also,GFS on that 13th forecast,
is showing the Sub polar jet re emerging
The speed of documentation is due to the short time frame available in snapping real time data.
Research of stuff like this.... after the event.... is frustrating since some data is not archived.
We have plenty here but still want to know the surface consequences.
Blink and thou may miss it.
There is plenty of time to sit back relax and reflect in the future .
Great you agree that... 'take a bit of time give it the time it deserves'
yes its late ....Night all..
...Click the calendar (it's archives go back years)!
Exactly take years of digestible chucks of imfomation,to get your head around.
Great discussion here guys. Sitting back and learning a thing or two. The Omega Block - saw it happening but didn't know the technical term for it. Great stuff.
GEE. really. That's gonna be very useful. Thanks
Its not unusual for a masters or a doctorate degree or even a research paper to take a year or two and even then there may be tentative conclusions and more research required
https://www.stratobserve.com/ is a great resource and thanks to Crikey for getting hold of it. Only reservation I have about it is the way anomalous eddy heat flux is represented - may have to contact the author to clarify
But in the context of the annual cycle of the polar stratospheric vortex, look how insignificant all this activity has been thus far
Which shows that there is something else additional to this, behind the current -AAO phase.
Perhaps...a dramatic shift in the temperature gradient could involve pole/equator/or both...the titling of this thread though is a bit restrictive to a broader inquiry
AAO is a southern hemisphere mean, it had many variations around the hemisphere at any time
Yes Pow thats my go to. At 70hpa the guess plot for the 16/7 is below, can only help our snow.
At 500 and 750hpa it looks great for more falls. The break remains and the cool air leaks north. Noice
Really think we need Sam..
....I'm not sure how helpful SAM is probably lacks the reliability of northern counterpart(paucity of stations?).
I cant recall seeing thickness values quite so low over TAS in days ahead- but I haven't really always been watching - also report https://www.washingtonpost.com/news...decades/?noredirect=on&utm_term=.e97f5125b897 as well snow in South Africa
so there may be something special and more generally happening currently
A couple of things to say here.
Keep in mind that what we were seeing was a warm pool over half the circumference of the polar and sub polar
and ......adjacent..... a cold pool half the circumference of the polar and sub polar stratosphere encircling around the pole.
It was not an overall even warming or cooling .,
So if you average the warm and cold pool you get about neutral or no anomaly.
I am not surprised at those graphs.
From your temp' anomaly chart above .
I am noting the cold anomaly in the 2-10hpa (-8 to minus 12 deg) occuring during April to July. The period of our investigation
The average mean wind anomaly surprises me. As you say nothing there. So,noting that as well.
any ideas on the something else.?
Come back to me in a few days time.
But planetary waves, the AAM/GWO (momentum transports), the QBO, Brewer-Dobson Circulation and the transitioning ENSO situation are all potential players here.
start a new thread @snowbarbie for temperature gradient between the tropics and poles.
Sounds like an interesting topic and you can go down an avenue that interests you.
Yes ..I would be interested too.
I suspect there was flattening of the temp' gradient around surface to 200hpa layers, from pole to say 50s, about the June , july 2019 period, interrupting the Ferrel cell flow.
It would explain the disappearance of the sub polar jet which relies heavily on latitudinal temp' differences l believe.
The AAO is a cycle. pos, neg, pos, neg..... forever.
I didn't even know you could measure the AAO from surface to stratosphere.until now
I thought it was a surface phenomena only.,
The only thing l can say is that AAO was highly positive during the period of this investigation, which usually means the sub polar jet is contracted south. The sub polar jet weakened in speed but was seen to be meridonal (wavy) .
A wavy sub polar jet is a weakened polar vortex l believe.
Sub polar jet is still recovering and very week this week.
There are signs of gradual recovery this week but l believe the week after is likely to be better.
The best hope is a 'left hand hook' from the westerly belt which looks to be the case this week as a low pressure bulge SE of the alps keeps things alive in the mean time
SAM is currently minus 1.5 and dropping . So northward excursion of westerly belt is 'on the cards'
Just hope the sub polar jet responds in tandem
An update on the surface and 200hpa recovery.
12th July 2019
The warming and cooling pools rotating around the 50hpa pole at sub polar region ,in stratosphere , is waning,/disappearing.
.That is not unusual, we have seen that phenomena before., in winters past
The di pole lows in the inner vortex have weakened and are likely to become one in the coming days
The 10hpa still has a 25deg c warm anomaly pool appearing and strengthened this past dew days. Possible upwelling
There is a warm anomaly over the Antartic during the period of investigation.
The sub tropical jet remains strong and zonal and is forecast to remain so this week.
The sub tropical jet is still largely non recognisable and forecast is showing a slow recovery .
The surface synoptic has returned to 'normality' today with high pressure ..centred.. over the pole
and surrounded by low pressure sub polar cells. The cells have already moved in to the organized phase and nodes are formed and have symetry
I will add the westerly belt is showing a migration northward consistent with a neg,AAO
Here are surface synoptic and 200hpa pictorial view. Both sourced from BOM ACC G
Unecessary since the discussion has already morphed away from "polar vortex split" and the pole to equator temperature gradient has as much to do with it as anything else
Happy to discuss equator to polar temperature gradient input into this event.
So lets say look at this from May to July 2019.
What data variables do you suggest.
Heights from say surface to 50hpa?
This is a new area for me so looking for some guidance here.
But l agree important to pursue and evaluate
Problem is getting hold of sufficient temp data and having the skills to analyse it and then to be able to say anything that's useful ?
If we take the polar and ST jets as proxy for temp gradient it may be easier to deal with. Still I'm not sure the charts of anomalous zonal winds below tell us enough. It's a sort of snapshot but very imprecise.
I haven't looked all that closely at what it might show - apart from the impression that ST and Polar jets are a combination of weaker/stronger and poleward/equatorward across the sectors during the period 15 june to present - arbitrary choice any dates you like can be used . The ST and Polar jets are visible generally - though merged jets need to be kept in mind. The hemisphere could be divided into even more sectors so you're getting down to more detail for particular longitudinal locations if desired.
0-90 Africa and Western IndianOcean.
90-180 Eastern Indian Ocean - Au - Western Pacific
180-270 Eastern Pacific
270 - 360 South America - Southern Atlantic
Thanks for the effort in collecting those wind anomaly charts.There are certainly some strong anomalies and l am not well versed in an accurate appraisal of them. My major area is weather cycle and pattern research, not meteorological weather dynamics
I am happy with what l have collected in jetstream analysis as l observe them frequently in the SH re patterns
My understanding of tropopause height is this. The tropopause is naturally higher at the equator and lower at the poles
The height of the tropopause depends on latitude, season, and whether it is day or night. Near the equator, the tropopause is about 20 km (12 miles or 65,000 feet) above sea level. In winter near the poles the tropopause is much lower. It is about 7 km (4 miles or 23,000 feet) high.
Given that it is an atmospheric thermocline it is likely there is some anomaly data available. .
Thanks to google form info and pics'
There are some great links here to investigate troposphere thermocline anomalies
Some excellent links to the experts in this area, from the link below
See what you think.
I am interested because ..if the cause is volcanic then this would show up,on the anomalies clearly and associated aftermath wave activity..
some basics posted here first
My first inquiry into volcanism in the SH as a possible input to our disturbance of the stratosphere and beyond
Mt Sinabung in Indonesia. 2 significant eruptions during our window of reference
.May7th and June 9th 2019
We won't have to do anything regard evaluating the atmospheric thermocline and other atmospheric anomalies.
Many researchers will be on to this .
We just need the links to follow their work and then link to our own investigation..for cross check
Got to say you have had a lot of fun with this!!
There are some links online to research mainly looking at when we got more than 3m and the link to the slight drop in temp the Volcanic dust would cause. We are on the edge literally in Australia -- 2c drop and its on. Like at present.
Ha..yes @Ret-ro. Some like the footy and some like the tennis some like the beer.
and some like 'chasing the wind'
Thanks for your interest.
I am going to start a dedicated thread on the eruption of mount Sinabung volcano and research that is currently underway to investigate its effect on southern hemisphere weather. .Just to tease things out.
My current knowledge is limited so an avenue to expand my understanding. I am sure there would be others interested.
This current thread will be ongoing for awhile , l am sure..
I would appreciate if you could posts some links or info' of what you are referring to when l open the new thread. thanks.
Have been thinking about the change to atmospheric thermocline as @snowbarbie as 'jasminestorm' have been suggesting.
I have thought of a simple way to possibly describe what may be going on.
The thermocline can be viewed side on . from equator.to pole.
There are also variations in the seasons to the thermocline.
I think we can link the disappearance and weakening of the sub polar jet to build a case for a strong anomalous dip in the thermocline for both the Ferrel and Polar circulation cells.
Here are my sticky notes/brain storming notes from my blog
Sticky notes..not conclusions.
What could happen if thermocline in the polar and ferrel cells were compromised.
Strong cold or warm anomalies at around 200 hpa at the top of these circulation cells
The troposphere could subside?
Geopotential height anomalies in the area of subsidence likely.
If thermocline temperature gradient disappears between ferrel and /or polar cell boundaries vertically and or horizontally?
at 200hpa. The jetstream would slow and may disappear.
The stratosphere, troposphere boundary may subside at ferrel, polar cell intersection which is about between 70 and 50s latitude.
A standing wave pattern may evolve in the stratosphere as a consequence of a steep
decline in thermocline between polar and ferrel cells.
Cold and warm anomaly dipole may emerge like the tipping of a pair of scales'
A lot to ponder there. I, for one, can't immediately think of any clear answers...but give me a little time I might be able to give it a go. One point - what do you mean by thermocline...it looks in this context to be tropopause..but not absolutely certain...second look befits temperature gradient?...can you clarify?
Thermocline is the term commonly used in ocean temperature ENSO reporting to describe warm and. cool upwellings or subsidence in the Pacific basin.
The term Temperature gradient would be a synonymous term to thermocline
I am seeing the term thermocline being used in atmospheric literature.
So either or .
Could we just make a wider big Stratosphere thread? So we can talk about everything Strat without much mandate.
There's clearly a number of people interested in it here now. Thoughts?
I certainly applaud the discussion we have here, although I can't really dig deeper into it until I leave Buller. Some great content from various people here.
..I agree...stratospheric warming/splitting....QBO...stratospheric-tropospheric exchange...whatever else...under one big umbrella rather than one long thread..but I'd like to hear especially from Crikey on all that.
I think it is great to have a dedicated thread for chat about all things stratosphere.
I would be there. It is an area that interests me
Choose the title wisely l suggest. For google bots and exactly what you want discussed there.
This thread is a personal research topic for me and your inputs have been valuable indeed.
I will continue here because the job is not yet done.
There are some updates re :further temp' anomaly activity in the upper stratosphere.
Which l will post later on.
May l suggest @Jellybeans and @snowbarbie that you host another thread for a more general and less restrictive content.
This thread is actually a case study in progress.and any contributions or comments are very welcome